Plastic bowling pin

ABSTRACT

This specification discloses a bowling pin of plastic that has the appearance of a wooden pin, sounds like a wooden pin, and scores like a wooden pin. These properties are imparted by the structure comprising a hollow main body, a hollow core with a space between the core and the body, a removable and replaceable cap plug for the upper end of the core, and a removable and replaceable base plug for the lower end of the core; and method of manufacturing the pin of this construction. The present invention relates to bowling pins, and is concurred primarily with a bowling pin of plastic that has all the properties that are of vital interest to a bowler, of a wooden pin and which properties are imparted to the pin by the structural characteristics thereof.

United States Patent [72] Inventor Maurice Anthony Negrini 3,232,616 2/1966 Conklin et al. 273/82 25 Quimby Ave, Wobum, Mass. 01801 3,329,430 7/1967 Wanders 273/82 [21] Appl. No. 882,036 7 Pfima ry Exammer-Rlchard C. Plnkham [22] Filed g s z ggg 836518 June 1969 Assistant Examiner-Richard J. Apley [45] Patented Mar. 31, 1971 Attorney-William Frederick Werner [4] PLASTIC BOWLING PIN ABSTRACT: This specification discloses a bowling pin. of plastic that has the appearance of a wooden pin, sounds like a 11 Claims, 7 Drawing Figs.

wooden pm, and scores like a wooden pm. These properties US. Cl. are imparted the structure comprising a hollow main body [5 1] A63! 9/00 a hollow core with a space between the core and the body, a Search removable and replageable cap for the upper end of 56 R f cted core, and a removable and replaceable base plug for the lower 1 e erences I end of the core; and method of manufacturing the pin of this constructior 814,257 3/1906 Wilson 273/82 The present invention relates to bowling pins, and is con- 2,517,1 l6 8/1950 Klinger 273/82 curred primarily with a bowling pin of plastic that has all the 3,044,777 7/1962 Friedman 273/82 properties that are of vital interest to a bowler, of a wooden 3,169,020 2/1965 Smith 273/82 pin and which properties are imparted to the pin by the struc- 3,l69,766 2/1965 Ernst 273/82 tural characteristics thereof.

52 ha, 5. /L i I 29L, C

i 3| BI PATENTED HARBO l9?! SHEET 1 OF 2 MAURICE ANTHONY NEGRINI .MWM um ATTORNEY PLASTIC BOWLING PIN This application is a division of Ser. No. 836,518 filed Jun. 25, 1969.

BACKGROUND OF THE INVENTION Bowling is a sport now meeting with widespread acceptance. Bowlers, by virtue of years of experience with wooden pins, now expect certain properties of the pins with which they play. Perhaps the most important of these properties is the sound which comes from impact with a ball, impact with each other as they fly about, and engagement with adjacent alley structure. If a plastic pin is to meet with public acceptance, it is believed it must sound like a wooden pin.

The manner in which one pin affects another as it engages therewith after being forcibly removed from its position of rest by impact with a ball or other pin is also of importance from the ,aspect of scoring. The total number of pins which are felled by the delivery of a ball depends on the reaction of the pins with each other and with environmental alley equipment. All such reactions should be the same as those derived from wooden pins.

All the pins of any set, whether duck pins, candle pins, or ten pins should be of uniform standard weight. Wooden pins are now produced in which this standardization of weight is achieved to a degree that is now acceptable. However, it is believed a more perfect attainment is desirable.

The part of a bowling pin which is subject to the greatest amount of wear is the base on which the pin rests in erected position. Next in wear reception is the cap or upper end. It is important that these elements be easily removable and replaceable.

While plastic bowling pins have been proposed, it is believed that none of the now available pins accommodate the above outlined factors to the degree necessary to accord to the pins the widespread acceptance with which wooden pins meet.

OBJECTS OF THE INVENTION SUMMARY OF THE INVENTION The foregoing objects are achieved by the plastic bowling pin of this invention. This pin comprises two main elements. There are: a main body and a hollow core. The body has an outer contour corresponding to that of a conventional pin and an inner cylindrical surface terminating in a shoulder at each end. Extending from each of these shoulders is a cylindrical surface of a diameter smaller than that between the shoulders, and which provides two bore sections of the same diameter and in alignment. These bore sections receive the core with an empty space or chamber being defined by the core, shoulders, and cylindrical surface therebetween.

Means are provided for maintaining the core assembled with the body. This means may take either of two forms. In one form transverse locking pins are employed. In the other embodiment the core is formed with outstanding ribs which engage the shoulders on the body to maintain the assembled relation.

The core has two bore sections of different radii with the larger in that portion within the body. A cap plug having an external locking flange is fitted into the free end of the smaller bore section with the flange being received in a groove. A base plug is removably fitted in the lower end of the larger bore section.

The method of manufacture consists essentially of extruding an appropriate plastic into a strip of a required cross section,

cutting a block of appropriate length from the strip, initially machining the outer surface of the block to approximate the contour of the finished pin, drilling'a central passage through the block, milling the interior of the block from the passage to form the passage to form the inner cylindrical surface, shoulders and bore sections and after assembly of the core finishing the outer contour.

Various other more detailed objects and advantages of the invention such as arise in connection with carrying out the above noted ideas in a practical embodiment will in part become apparent and in part be hereinafter stated as the description of the invention proceeds.

For a full and more complete understanding of the invention reference may be had to the following description and accompanying drawings wherein:

FIG. 1 is a perspective of a bowling pin embodying the present invention.

FIG. 2 is a vertical section through the pin being taken about on the plane represented by the line 2-2 of FIG. 1.

FIG. 3 is a horizontal section taken about on the plane represented by the line 3-3 of FIG. 2.

FIG. 4 is a perspective illustrating the elements of the pin in exploded relation.

FIG. 5 is a vertical section through a modification.

FIG. 6 is a detailed perspective depicting the elements at the upper end in exploded relation.

FIG. 7 is a detailed exploded perspective of the lower end.

Before referring to the drawings it is noted that the subject pin may be made of any of the now known plastics having the required properties of strength, resilence and machinability. However, polystyrene may be taken as the preferred material. Also while a duck pin is illustrated, the invention is applicable to other types of pins such as ten pins or candle pins.

Referring now to the drawings, and first more particularly to FIGS. 1 to 4 inclusive, the bowling pin of this invention is shown as comprising a body identified in its entirety as B and a core designated generally at C. Body B has an outer contour of a curvature corresponding to that of a conventional pin. The outer surface is designated 10 and terminates at an upper edge 11 and a lower edge 12. Extending inwardly from edge 11 is an upper bore section 13 (FIG. 2) which terminates in a shoulder 14.

Extending inwardly from edge 12 is a lower bore section 15 terminating in a shoulder 16. Between shoulders 14 and I6 is a cylindrical surface 17. Entering body B form bore section 13 is a closed end recess or socket l8. Diametrically opposed and in alignment with socket 18 is a passage 19 that extends from outer surface 10 to bore section 13. Spaced inwardly from lower edge 12 are two passages 20 in alignment. Each passage 20 extends from surface 10 to bore section 15.

Core C has an outer contour comprising a convex surface 21 and a concave surface 22 at its upper end. These surfaces 21 and 22 have a curvature that imparts a contour to the upper portion of the core similar to that of the corresponding part of a conventional pin.

Joining concave surface 22 at its lower edge is a cylindrical surface 23 (FIG. 4) of a diameter near enough to that of bore section 13 to provide a close fit therewithin when the core C is assembled in body B. Cylindrical surface 23 terminates at a conical surface 24 (FIG. 2). Extending below conical surface 24 is a cylindrical surface 25 that stops at a lower conical surface 26. From the latter a cylindrical surface 27 extends to a conical surface 28 at the end of core C.

Core C is hollow with the hollow structure being provided.

That portion of core C defined by cylindrical surface 27 is also formed with aligned passages 36 which also align with passages 20. A locking pin 37 passes through these passages and complete the means for maintaining core C assembled in body B.

A cap plug 38, preferably of nylon, has an external flange 39 at its lower end and this plug is received in the upper end of bore 29 with flange 29 seating in groove 30 to maintain the assembled relation. Plug 38 is removableand replaceable. A base plug, also of nylon, comprises a tubular portion 40 and a conical end portion 41 separated from tubular portion 40 by a flat shoulder 42. Tubular portion 41 is formed with aligned passages 43 which also align with passages 20 and 36 and pin 37 passes therethrough to maintain the base plug assembled with the core and body.

End portion 41 of the base plug has a recess 44 in it lower flat bore which is conventional.

It is notable that cylindrical surface 17 and shoulders 14 and 16 of body B, together with cylindrical surface 25 of core C define an empty space or chamber 45 that functions much in he manner of a sound box in determining the sound generated by a ball striking the pin, and pins engaging each other and alley equipment.

In the manufacture of the pin above described, the plastic (polystyrene) is extruded into a strip of appropriate cross section. A block of a length corresponding to body C is cut from this strip. This block is machined to achieve an outer contour approximately that of surface 10. It is then drilled to form a central passage which ultimately provides bore sections 13 and 15. It is the milled internally from this passage to form shoulders 14 and 16 and inner cylindrical surface 17. Socket 18 and passages 19 and 20 are then formed by drilling.

Core C is preferably also formed from an extruded strip with a block of proper length being cut therefrom. Outer surfaces 21 and 22 are then rough finished after which the block is drilled from its opposite ends to form bores 29 and 32. Shoulder 24 and 26 and cylindrical surface 25 are then formed by milling. Passages 34 and 36 are then drilled.

Cap plug 38 and the base plug are extruded and finished. After the parts are assembled as above described all of the outer surfaces are finally finished. This finishing also enters into accurately achieving the standard weight.

Referring now to FIGS. 5, 6 and 7 a modified form of invention will be described. Body B of FIG. is substantially the same as body B with the exception of the omission of the passages which receive the locking pins. There are, however, some important distinctions between core C of FIGS. 1 to 4 and core C ofFlG. 5.

Core C has the same upper bore 29 terminating in shoulder 31 of core C. However, throughout the extent of lower bore 32 core c is of uniform wall thickness with the exception of a lower external rib 46 which presents a shoulder 47 that is in abutting engagement with shoulder 16 of body B. Core C" also has an upper 48 defined by a conical surface 49 of small pitch and an upper flat shoulder 50 which engages shoulder 14,

of body B alter assembly.

In assembling core C with body B the core is inserted from the top in the usual way. Due to the hollow construction of the core and the elastic and resilient nature of the plastic from which it is made ribs 46 and 48 will ride past bore section 13. At the time shoulder 16 and 47 abut shoulder 50 is disposed opposite to shoulder 14 and will snap out into the expanded holding position illustrated in FIG. 5.

Considering FIG. 6 along with FIG. 5 it will be noted groove 51 in core C has a sharp or abrupt upper shoulder 52. Flange 53 in cap plug 54 has lower conical surface 55 and an upper flat ring like shoulder 56. As the plug 54 is inserted conical surface 55 aids in flange 53 riding down bore 29 until shoulder 56 comes opposite to shoulder 52. Flange 53 then expands into groove 51 to achieve its holding position.

FIG. 5 shows the lower end of core C formed with a groove 57 opening into bore 32. As depicted in FIG. 7, a base plug includes a tubular portion 58 which before complete assembly has an uninterrupted outer cylindrical contour. It also is formed with a smooth bore 60.

Bore 60 terminates in a lower flared end 61. A locking plug 62, which like plug 58 is of nylon, has an external flange 63.

In assembly base plug 58 is first inserted into bore 32. Locking plug 62 is now inserted in bore 60. Flange 63 will ride along bore 60 until it comes opposite to the groove 57. Due to the flexible and yieldable properties of the nylon form which plug 58 is made, and the more solid construction of the locking plug 62, flange 63 will distort plug 58 to force a portion thereof into groove 57 and thus form retaining flange 59 as shown in FIG. 5.

As an alternative this flange 59 may be initially formed on base plug 58 and a groove there opposite opening into bore Base B and core C may be manufacture in the same way as described in conjunction with base B and core C with the exception that the transverse passages are not drilled.

While preferred specific embodiments of the invention are hereinbefore set forth, it is to be clearly understood that the invention, is not to be limited to the exact construction, materials and steps illustrated and described because various modifications of these details may be provided in putting the invention into practice.

Iclaim:

1. In a plastic bowling pin,

a. a body having an outer contour defined by a surface terminating in end edges, an upper bore section extending into said body at one end and terminating in a shoulder, a lower bore section extending into said body from the other end edge and terminating in a shoulder, and an inner cylindrical surface wider than said upper and lower bore sections located between said shoulders;

b. a hollow core having an outer surface including an upper portion having a convex-concave formation, spaced cylindrical sections received in said bore sections, an intermediate section formed between said cylindrical sections and having an outer surface spaced from said inner cylindrical surface of the body to form a chamber therebetween; and

0. means to maintain said core assembled in said body.

2. The bowling pin of claim 1 together with a cap plug of nylon removably received in the upper end of said hollow core.

3. The bowling pin ofclaim 2 in which the core has an upper bore with a groove opening thereinto and the cap plug has a flange received in the groove.

4. The bowling pin of claim 1 together with a base plug of nylon removably received in the lower end of said hollow core.

5. The bowling pin of claim 1 in which the means for maintaining the assembled relation comprises a pair of transverse locking pins extending through aligned passages in said body and core.

6. The bowling pin of claim 5 together with a base plug of nylon secured in the lower end of the core by one of said pins.

7. The bowling pin of claim 1 in which the means for maintaining the assembled relation comprises external ribs on the intermediate section of the core and which present flat shoulder portions for engaging said shoulders on the body.

8. The bowling pin of claim 7 in which one of said ribs has a low pitch conical surface which facilitates insertion of the core into the body.

9. The bowling pin of claim 2 in which the core has an upper bore having a groove opening thereunto and which groove has an abrupt upper shoulder and the cap plug has an external flange defined by a conical surface and an abrupt shoulder that engages the shoulder on the core.

10. The bowling pin of claim 1 in which the hollow core has a lower bore and a groove opening thereunto, a base plug of nylon and including a tubular portion recieved in said lower base, and a locking plug in said tubular portion and formed with an external flange that forces part of said tubular portion into said groovewhen the locking plug is inserted in said base received in said groove, said tubular portion of the base plug p also having an internal groove; and an external flange on the 11. The locking plug of claim 1 in which the'hollow core has a lower bore with a groove opening thereunto, a base Plu igg ggf gfi m the groove f sald tubular pomon of having a tubular portion received in said bore, a locking plug 5 in said tubular portion, an external flange on said locking plug 

1. In a plastic bowling pin, a. a body having an outer contour defined by a surface terminating in end edges, an upper bore section extending into said body at one end and terminating in a shoulder, a lower bore section extending into said body from the other end edge and terminating in a shoulder, and an inner cylindrical surface wider than said upper and lower bore sections located between said shoulders; b. a hollow core having an outer surface including an upper portion having a convex-concave formation, spaced cylindrical sections received in said bore sections, an intermediate section formed between said cylindrical sections and having an outer surface spaced from said inner cylindrical surface of the body to form a chamber therebetween; and c. means to maintain said core assembled in said body.
 2. The bowling pin of claim 1 together with a cap plug of nylon removably received in the upper end of said hollow core.
 3. The bowling pin of claim 2 in which the core has an upper bore with a groove opening thereinto and the cap pluG has a flange received in the groove.
 4. The bowling pin of claim 1 together with a base plug of nylon removably received in the lower end of said hollow core.
 5. The bowling pin of claim 1 in which the means for maintaining the assembled relation comprises a pair of transverse locking pins extending through aligned passages in said body and core.
 6. The bowling pin of claim 5 together with a base plug of nylon secured in the lower end of the core by one of said pins.
 7. The bowling pin of claim 1 in which the means for maintaining the assembled relation comprises external ribs on the intermediate section of the core and which present flat shoulder portions for engaging said shoulders on the body.
 8. The bowling pin of claim 7 in which one of said ribs has a low pitch conical surface which facilitates insertion of the core into the body.
 9. The bowling pin of claim 2 in which the core has an upper bore having a groove opening thereunto and which groove has an abrupt upper shoulder and the cap plug has an external flange defined by a conical surface and an abrupt shoulder that engages the shoulder on the core.
 10. The bowling pin of claim 1 in which the hollow core has a lower bore and a groove opening thereunto, a base plug of nylon and including a tubular portion recieved in said lower base, and a locking plug in said tubular portion and formed with an external flange that forces part of said tubular portion into said groove when the locking plug is inserted in said base plug.
 11. The locking plug of claim 1 in which the hollow core has a lower bore with a groove opening thereunto, a base plug having a tubular portion received in said bore, a locking plug in said tubular portion, an external flange on said locking plug received in said groove, said tubular portion of the base plug also having an internal groove; and an external flange on the locking plug received in the groove of said tubular portion of the base plug. 